ViewTopic.php -> when the results of SORT_DAYS returns zero posts, the sort select options and the ‘Return to … ‘ navigation back to the parent topic are no longer visible to the user. The user receives the NO_POSTS_TIME_FRAME from the trigger_error but can no longer navigate back. This behavior and code are handled differently in ViewForum.php -> when the results of the SORT_DAYS returns zero topics, the user receives the NO_TOPICS message as part of the template and still has the ability to query again by updating the S_SELECT options or to ‘Return to … ‘ to navigate up the forum.